420037B14 is a large-format machined aluminum control knob from the 42003 series featuring a diamond knurl plastic insert and side-mounted line indicator. The knob has a maximum diameter of 1.252 inches (31.8 mm) with a height of 0.980 inches (24.9 mm), designed specifically for 1/4" diameter shafts. It is constructed from machined aluminum with a brass threaded insert and includes heat-treated high alloy steel set screws with cup points for secure shaft retention. The knob is available in natural anodized finish and is functionally rugged with positive retention, making it suitable for control panel applications, instrumentation, and equipment requiring reliable manual adjustment with clear position indication.